Three ticks for liqueur (6,3)
I believe the answer is:
triple sec
'liqueur' is the definition.
(triple sec is a kind of liqueur)
'three ticks' is the wordplay.
I cannot quite see how this works, but
'three' could be 'tri' (prefix meaning 'three') and 'tri' is found in the answer.
This explanation may well be incorrect...
'for' is the link.
Can you help me to learn more?
(Other definitions for triple sec that I've seen before include "Strong orange-flavoured liqueur - perils etc (anag)" , "Drink" , "alcohol" .)